1. Field
This application relates generally to wireless communication and more specifically, but not exclusively, to transmit power control schemes.
2. Introduction
A wireless communication network may be deployed over a defined geographical area to provide various types of services (e.g., voice, data, multimedia services, etc.) to users within that geographical area. In a typical implementation, access points (e.g., corresponding to different macro cells) are distributed throughout a network to provide wireless connectivity for access terminals (e.g., cell phones) that are operating within the geographical area served by the network.
As the demand for high-rate and multimedia data services rapidly grows, there lies a challenge to implement efficient and robust communication systems with enhanced performance. To supplement conventional network access points (e.g., macro access points), small-coverage access points may be deployed (e.g., installed in a user's home) to provide more robust indoor wireless coverage or other coverage to mobile units. Such small-coverage access points may be referred to as, for example, femto cells, femto access points, access point base stations, home NodeBs, or home eNodeBs. Typically, such small-coverage base stations are connected to the Internet and the mobile operator's network via a DSL router or a cable modem.
In general, at a given point in time, an access terminal will be served by a given one of the access points in a network. As the access terminal roams throughout the network, the access terminal may move closer to another access point. Under certain circumstances, the access terminal may then reselect to the other access point (e.g., be handed-over from its current serving access point to the other access point). For example, to enable an access terminal to access the services provided by an associated femto cell (e.g., a home femto cell), it may be desirable to hand-over the access terminal from a current serving macro cell to the femto cell as soon as the access terminal enters the coverage area of the femto cell.
Accordingly, there is a need for techniques to ensure that an access terminal (e.g., idle user equipment) consistently discovers and reselects to a femto cell when the access terminal arrives at the femto cell. Moreover, it is desirable to achieve this irrespective of the location of the femto cell (e.g., the proximity of the femto cell to the macro access point) and without significantly affecting the coverage of the macro cell (e.g., without creating outage areas for access terminals communicating with the macro cell).